Do you often feel fatigued during the day, even after getting enough sleep? You may be wondering if you have narcolepsy or chronic fatigue syndrome. Both of these conditions can make it hard to stay awake during the day.

Chronic fatigue syndrome, also known as myalgic encephalomyelitis or ME/CFS, is severe, persistent fatigue that isn’t relieved by rest. ME/CFS is a complicated medical condition that isn’t caused by another medical or psychological condition.

Although some of the symptoms of narcolepsy and ME/CFS are similar, they have different underlying causes, diagnoses, and treatments.

Symptoms of Narcolepsy

Narcolepsy and ME/CFS can cause extreme fatigue. In fact, many of the symptoms of ME/CFS can mimic those of other sleep disorders, like narcolepsy.

The symptoms of narcolepsy include:

• Excessive daytime sleepiness — Feeling sleepy during the day even after getting enough sleep at night
• Sudden sleep attacks — Falling asleep suddenly and uncontrollably, even during inappropriate times like while talking, eating, or driving
• Sudden loss of muscle tone — Also called cataplexy, this temporary muscle weakness is often triggered by strong emotions like laughter or anger
• Sleep paralysis — Waking up and being temporarily unable to move or speak, which can be very frightening
• Hallucinations — Experiencing vivid, dreamlike hallucinations when falling asleep or waking up

Narcolepsy usually does not cause any serious, long-term health problems but can have a big impact on your quality of life and mental health.

Symptoms of Chronic Fatigue Syndrome

The symptoms of chronic fatigue syndrome vary from person to person. Some common symptoms include:

• Fatigue — An overwhelming feeling of tiredness or exhaustion that is not improved with rest
• Post-exertional malaise — Worsening symptoms after periods of mental or physical activity
• Orthostatic intolerance — Feeling dizzy when you go from lying down to sitting up or standing
• Sleep problems — Difficulty falling asleep, staying asleep, or feeling rested after sleep
• Cognitive problems — Trouble thinking, concentrating, and remembering things, often described as brain fog
• Flu-like symptoms — Muscle pain, headache, sore throat, and swollen glands (lymph nodes)
• Increased sensitivity — Being more sensitive to lights, sounds, smells, and medicines

Symptoms of ME/CFS can be unpredictable, meaning that the symptoms may not always be present and may vary in intensity. Sometimes, the symptoms may get better, and other times they may get worse. The symptoms may also change over time, making it challenging to manage the condition.

How Common Are These Conditions?

Estimating the prevalence (how many people in a certain group have a particular condition over a specific time period) of narcolepsy and chronic fatigue syndrome is challenging because it is difficult to diagnose these conditions. Narcolepsy is a rare disease. Research suggests that about 25 to 50 people out of 100,000 have narcolepsy around the world.

The Centers for Disease Control and Prevention (CDC) estimates that between 836,000 and 2.5 million Americans have ME/CFS. One study estimated that 71 people out of 100,000 have chronic fatigue syndrome.

Causes

The exact cause of narcolepsy or ME/CFS is still unknown. It is thought that the immune system may play a role in the development of both narcolepsy and CFS.

There are two types of narcolepsy — type 1 and type 2. Although researchers don’t understand as much about why type 2 occurs, they know more about type 1. It is believed that type 1 narcolepsy is related to low levels of a chemical in the brain called hypocretin (also called orexin) that helps you regulate wakefulness and rapid eye movement (REM) sleep. In people with type 1 narcolepsy, the immune system mistakenly attacks cells in the brain that produce hypocretin, leading to a shortage of this chemical. The reason that your immune system attacks these cells is unknown but is believed to involve a combination of genetic and environmental factors. In type 2 narcolepsy, the levels of hypocretin are normal and affected individuals don’t have cataplexy.

The cause of ME/CFS is controversial, but it is thought that it may be triggered by a combination of factors, including genetics, immune disease, vaccination, trauma, tumors, neurodegenerative disorders such as Parkinson’s disease and Alzheimer’s disease, vascular disease, and infections.

Who Gets Narcolepsy or Chronic Fatigue Syndrome?

Although anyone can get either of these conditions, certain risk factors can make it more likely to be diagnosed with one or the other.

Risk factors for narcolepsy include:

• Male sex — People assigned male at birth have an increased risk of narcolepsy.
• Age — Most people are diagnosed between the ages of 10 and 30.
• Family history — If you are related to someone with narcolepsy, your risk of narcolepsy might be 20 to 40 times higher.
• Head injury — A head injury that damages the area of the brain that controls sleep and wakefulness may increase the risk of developing narcolepsy.

Risk factors for chronic fatigue syndrome include:

• Female sex — People assigned female at birth are more likely to be diagnosed with chronic fatigue syndrome.
• Age — ME/CFS most commonly affects people between the ages of 40 and 60.
• Family history — You may be more likely to be diagnosed with ME/CFS if you have a relative with the disease.
• Previous infections — Some people develop ME/CFS after recovering from an infection.
• Trauma — Some people develop ME/CFS after experiencing physical or emotional trauma.
• Other medical conditions — ME/CFS is associated with other medical conditions such as fibromyalgia.

Diagnosis

Consider making an appointment with your primary care physician if you are experiencing excessive daytime drowsiness or extreme fatigue that affects your daily life. However, receiving a diagnosis for narcolepsy or ME/CFS can be challenging and takes time.

Many of the diagnostic tests for narcolepsy and ME/CFS are the same.

Your doctor may send you to a sleep specialist — a doctor (such as a neurologist, pulmonologist, or psychiatrist) that has extra training in sleep medicine.

The sleep specialist may ask you questions about your sleep history and ask you to record your sleep patterns for a few weeks. If they suspect you have type 1 narcolepsy, they may order a lumbar puncture (spinal tap) to check the level of hypocretin in your spinal fluid.

The sleep specialist may also ask you to stay at a medical facility for a sleep study, such as:

• Polysomnography — A test that measures your heart rate, breathing rate, eye movements, leg movements, and brain waves while you sleep overnight
• Multiple sleep latency test — A test that measures how fast you fall asleep during the day by having you take multiple naps

Diagnosis of Chronic Fatigue Syndrome

There is no specific test for ME/CFS, but your doctor may run blood tests to check for other possible causes of your symptoms, such as sleep disorders, mental health disorders, or other medical conditions. A diagnosis of ME/CFS requires all other causes of fatigue, including narcolepsy, to be ruled out.

Other health conditions that may cause fatigue include:

• Anemia (low red blood cells)
• Underactive thyroid
• Diabetes
• Kidney problems
• Liver problems
• Immune system disorders

To be diagnosed with ME/CFS, you must experience moderate or severe symptoms most of the time for at least six months. The United States Institute of Medicine diagnostic criteria include the following symptoms: fatigue, post-exertional malaise, and unrefreshing sleep. Additionally, you must experience at least one of the following symptoms: dizziness that gets worse with sitting or standing or cognitive problems.

Treatment

There isn’t a cure for either narcolepsy or CFS. However, medications and lifestyle changes can help improve symptoms.

Narcolepsy Medications

Narcolepsy treatment can include several different types of medications to help relieve symptoms. Stimulant medications are the primary treatment option to help people with narcolepsy stay awake and alert during the day.

To improve sleep, reduce hallucinations, and treat cataplexy, your doctor may prescribe an antidepressant such as selective serotonin reuptake inhibitors (SSRIs), serotonin and norepinephrine reuptake inhibitors (SNRIs), or tricyclic antidepressants.

Sodium oxybate (Xyrem) and oxybate salts (Xywav) are sleep medications approved specifically to treat symptoms of narcolepsy.

Talk to your doctor about the best treatment for your narcolepsy symptoms and any potential side effects of the medications.

Chronic Fatigue Syndrome Medications

There aren’t any medications to specifically treat ME/CFS. Your doctor will prescribe medications based on your symptoms. Common medications used to treat ME/CFS include antidepressants, pain medications, blood pressure medications, and nutritional supplements.

Talk to your doctor about the best treatment options for your symptoms. If you suspect a vitamin deficiency, make sure to be properly evaluated by your doctor before you start taking a nutritional supplement.

Lifestyle Changes

Lifestyle changes can be helpful for both conditions. Some helpful recommendations include:

• Go to sleep and wake up at the same time every day.
• Take short naps during the day, if possible.
• Pace yourself to avoid post-exertional malaise.
• Get regular exercise.
• Avoid alcohol.
• Eat a balanced diet.

Your health care provider can give you more advice on lifestyle changes that might benefit you the most.

Although narcolepsy and chronic fatigue syndrome have similar symptoms, they are different conditions with unique causes and treatments. Narcolepsy results from a shortage of hypocretin in the brain, while the cause of chronic fatigue syndrome is still not well understood. Treatment options for narcolepsy involve drugs that regulate sleep cycles, whereas managing chronic fatigue syndrome may include exercise and medication. If you suspect you may have one of these conditions, it’s essential to talk to a health care provider for an accurate diagnosis and personalized treatment plan.

Talk With Others Who Understand

MyNarcolepsyTeam is the social network for people with narcolepsy and their loved ones. On MyNarcolepsyTeam, more than 10,000 members come together to ask questions, give advice, and share their stories with others who understand life with narcolepsy.

Have you been diagnosed with narcolepsy or chronic fatigue syndrome? Share your experience in the comments below, or start a conversation by posting on your Activities page.